Weaving device

ABSTRACT

The invention relates to a weaving device comprising means for forming a shed consisting of warp yarns, with insertion means being disposed on one side or on both sides of the shed for inserting a weft yarn into the shed. The object of the invention is to provide a weaving device as referred to in the introduction, which weaving device is of significantly simplified construction and which is much simpler to control. According to the invention, the weaving device is to that end characterized in that the weft yarn has been formed into a packed clew, which packed clew unwinds into an elongated weft yarn upon insertion into the shed. These aspects obviate the need to use a projectile having a high inert mass and the related insertion means and braking means for moving and decelerating the movement of the projectile through the shed, resulting in a weaving device of significantly simplified construction, which is much simpler to control and which can be operated at a much higher rate.

The invention relates to a weaving device comprising means for forming ashed consisting of warp yarns, with insertion means being disposed onone side or on both sides of the shed for inserting a weft yarn into theshed.

Weaving devices of the above kind are generally known, for example fromDutch patent application No. 73/09850. With this type of weavingdevices, a weft yarn from a supply bobbin is connected to a projectile,also called shuttle, which projectile is launched by the insertion meansdisposed on either side of the shed, using a medium under pressure, forexample compressed air, and carried through the shed via guides disposedin the shed.

A drawback of this known device is the fact that all the energy requiredfor moving the projectile through the shed must be imparted to theprojectile at the beginning of the movement, i.e. at the location of theinsertion means. In order to be able to carry the projectile through ashed of reasonable width, a large amount of energy has be supplied tothe projectile at the beginning of its movement, which means a very highinitial velocity, resulting in high peak tensions in the weft yarn to betransported. Furthermore this means that the projectile needs to have afairly high inert mass. These aspects of the known weaving device imposelimitations on the functionality thereof as regards the speed, thecomplexity and the maximum width of the fabric to be manufactured.

The above limitations are partially overcome by a weaving device asdescribed in Dutch patent application No. 1004173. In this weavingdevice auxiliary blowers are disposed in the shed, which auxiliaryblowers are provided with outflow openings for the medium under pressurethat impacts on an impact surface of the projectile to be guided duringoperation so as to assist in the movement of the projectile through theshed. Using these aspects, it is no longer necessary to impart all theenergy required for carrying the projectile through the shed to theprojectile at the beginning of the shed. Although in fact the width ofthe shed is no longer bound by limitations when auxiliary blowers areused, it is still necessary to use a projectile having a high inertmass, and this embodiment of a known weaving device is more complex asregards its construction and control.

The object of the invention is to provide a weaving device as referredto in the introduction, which weaving device is of significantlysimplified construction and which is much simpler to control. Accordingto the invention, the weaving device is to that end characterized inthat the weft yarn has been formed into a packed clew, which packed clewunwinds into an elongated weft yarn upon insertion into the shed. Theabove aspects obviate the need to use a projectile having a high inertmass and the related insertion means and braking means for moving anddecelerating the movement of the projectile through the shed, resultingin a weaving device which is of significantly simplified constructionand which is much simpler to control.

The lighter components (no heavy components are used) furthermore enablea much greater speed of operation of the weaving device according to theinvention, which means high-speed weaving, for example with a muchgreater insertion speed, in terms of time, of weft yarns into the shed.More particularly, it is the clew rather than the yarn itself on whichthe forces are exerted upon insertion thereof. Now that no loose yarnsare individually inserted into the shed any more, with a clewed weftyarn being inserted, peak tensions in the yarn are prevented, since itis the clew (rather than a yarn) that is now subjected to theacceleration forces that are exerted by the insertion means uponinsertion.

Since the unwinding of the clew into a weft yarn upon insertion into theshed takes place in a gradual manner, a substantially constant, lowtension is present in the weft yarn, without the peak tension thatusually occurs during the sudden braking action that takes place in thecurrently known weaving machines.

In a specific embodiment, in order to effect an improved unwinding ofthe packed clew into an elongated weft yarn in the shed, the insertionmeans are arranged to fix the packed clew upon insertion into the shedat a yarn section that projects from the clew. To that end, theinsertion means may comprise a gripping element for fixing the yarnsection.

According to the invention, in order to guarantee the correctfunctioning of the weaving device during operation and thus preventfailure, standstill or jamming of the weaving device and obtain anoptimum weaving result, the packed clew has its own consistent shape.

In a specific embodiment, in order to guarantee a correct insertion ofthe clewed weft yarn during operation of the weaving device, the weftyarn of the packed clew is provided-with a bonding agent, for example aglue or a wax. In another embodiment, ice is used as the bonding agent,more in particular “dry ice”.

In another embodiment of the weaving device according to the invention,the packed clew can be moved through the shed by means of a carrier. Thepacked clew may be arranged round the carrier in one or more windings;in a specific embodiment, the carrier envelopes the packed clew at leastpartially. In the latter embodiment, the packed clew does not need tohave a consistent shape, but the clew retains its shape as a result ofthe presence of the envelope.

After being inserted, the clew unwinds during its movement through theshed. The moment the clew has unwound into an elongated weft yarn, thecarrier envelope may be intercepted at the end of the shed and bedischarged, for example for forming a new clew.

In a specific embodiment, the carrier is made of a rigid material, forexample a plastic, or of a flexible material, for example a foil. Inboth embodiments the clewed weft yarn is given a consistent externalshape, which still has a certain inert mass, however.

In a specific embodiment, the insertion means comprise an elongatedtube, which tube is directed towards the shed with an open end thereofand which can be connected to means for supplying the medium underpressure at its other end. Said medium under pressure may be compressedair or water.

In a specific embodiment of a clewed weft yarn, the weft yarn has acertain, limited length, having at least one end projecting from theclew. In another functional embodiment, several clewed weft yarns areinterconnected via intermediate yarn sections, which clewed weft yarnscan subsequently be inserted into the shed one after another by theinsertion means. Said several clewed weft yarns may be formed of oneyarn, which clewed weft yarns may be present on a winding element in oneor more windings.

The invention also relates to a weft yarn as described in the presentapplication.

The invention will now be explained in more detail with reference to adrawing, in which:

FIGS. 1 and 2 show a weaving device according to the prior art;

FIGS. 3 a-3 e show various embodiments of a clewed weft yarn accordingto the invention;

FIG. 4 shows an embodiment of the insertion means of a weaving deviceaccording to the invention;

FIGS. 5 a-5 b show further aspects of the invention.

In FIGS. 1 and 2 an embodiment of a known weaving device is shown, forexample the device that is described in Dutch patent application No.73/09850 or Dutch patent No. 1004173.

The known weaving device comprises a lay 1 and means 2 for forming ashed 3 of warp yarns 4, which warp yarns 4 come from warp yarn supplybobbins 5. A large number of dents 6, together forming the so-called“reed”, are arranged on the lay 1, which dents can move between the warpyarns 4. A number of guides 7 are furthermore arranged on the lay 1 forguiding a projectile 8 from one side to the other side.

As is shown in the figure, the projectile 8 is present in an insertionstation 9 disposed on the left-hand side of the shed 3, whilst a brakingstation 10 is disposed at the other side of the shed 3. A weft yarn 11from a supply bobbin 12 can be connected to the projectile 8 in a knownmanner. A considerable amount of impulse energy is imparted to theprojectile 8 by means of a medium under pressure, for example compressedair or water. As a result, the projectile 8 undergoes an accelerationand is moved or “shot” through the shed 3 at a high velocity, carryingalong the weft yarn 11. The projectile 8 is also called the shuttle,therefore.

The projectile 8 that moves through the shed 3 at a high velocity mustbe decelerated on the other side of the shed 3 (on the right in FIG. 1).To that end, a braking station 10 is disposed directly beside the shed33 which station 10 intercepts and decelerates the projectile as itleaves the shed 3. Likewise, the projectile 8 can be moved (“shot”) fromthe right-hand side to the left-hand side of the shed 3 at a highvelocity by an insertion station 93 (not shown) arranged analogously tothe insertion station 9, which is disposed on the right-hand side of theshed 3.

A braking station 10′ (not shown) is furthermore disposed at thelocation of the insertion station 9 for intercepting and decelerating aprojectile 8 moving from the right-hand side to the left-hand side ofthe shed 3.

The high inert mass of the projectile 8 and the frequently considerablewidth L of the shed 3 require that the projectile 8 be moved through theshed 3 at a relatively high velocity. The acceleration forces thusgenerated lead to undesirable peak tensions in the weft yarn 11 beingcarried along, which may cause the yarn to break. In addition to that,the projectile 8 moving through the shed at a high velocity must beintercepted at the end of the shed and be decelerated by a separatebraking station 10 (10′). Said deceleration, too, may lead toundesirable peak tensions in the weft yarn, especially in situations inwhich the weft yarn is used for decelerating the projectile.

In order to prevent in particular the undesirable peak tensions in theweft yarn 11, a lower initial speed of the projectile 8 being “shot”through the shed 3 is required, which also limits the maximum width ofthe shed 3, however. In the prior art it has already been proposed toembody the guides 7 that primarily function to guide the movement of theprojectile 8 through the shed 3 as medium blowers. Said medium blowers 7are mounted on the lay 1 and are connected to a medium supply line 17.Each guides 7 may be connected to a main medium supply line 19 via anelectromagnetic valve 18.

Each guide 7 is provided with medium outflow openings (not shown inFIG. 1) oriented in the direction of transport of the projectile 8. Themedium outflow openings are directed towards an impact surface of theprojectile 8, so that the pressurised medium flowing out of the openingswill impact on said impact surface and thus transmit the energy from themedium to the projectile 8. The auxiliary blowers 7 thus assist in themovement of the projectile 8 through a shed 3, thus obviating the needfor a high initial speed to be imparted to the projectile by theinsertion station 9.

This configuration of a known weaving device in any case leads to lowerpeak tensions in the weft yarn 11. The braking stations 10 fordecelerating the weft yarn 11 and the projectile 8 arriving from theshed are still necessary, costly components of the weaving device, sothat the known weaving devices still exhibit a certain degree ofcomplexity.

FIGS. 3 a-3 d show specific embodiments of an important aspect of theweaving device according to the invention.

According to the invention, the weft yarn 11 has been formed into a clew20, which is preferably given a consistent shape by using a binding orbonding agent 22, for example. In FIG. 3 a, said binding or bondingagent 22 may be a glue. Also wax appears to be very suitable for givingthe left yarn 11 a consistent shape, however. The bonding agent preventsthe clew 20 from falling apart into a loose mass of yarn during itsmovement through the shed 3, which would inevitably lead to weavingfaults and/or failure of the device.

By fixing the clew 20 at a yarn section 21 projecting from the clew 20,the clew 20 is unwound or uncoiled into an elongated, fully uncoiledweft yarn 11 during its movement through the shed 3. According to theinvention, each clew 20, once it is fully uncoiled, thus has a lengthequal to the width L of the shed 3. See also FIG. 4.

FIGS. 3 b and 3 c show other embodiments of the weft yarn 11 formed intoa clew 20, which is surrounded by carriers 23 and 24, respectively. InFIGS. 3 b, the carrier 23 is in the form of an encasing of a hard yetlight plastic, which surrounds the clew 20. The sleeve is provided withan opening 23 a, which enables placement of the clew 23 into theencasing prior to insertion of the assembly into the shed on the onehand and unwinding of the clew 20 present in the encasing 23 on theother hand.

The moment the clew 20 has fully unwound into an elongated weft yarn 11,the carrier 23 will leave the shed 3 to be intercepted outside the shed3, for example for reuse.

FIG. 3 c shows a similar embodiment, in which the carrier is made of aflexible material, for example a foil. Analogously to the embodiment ofFIG. 3 b, the clew 20 does not have a consistent shape of itself in thisembodiment, its shape being determined by the carrier 24 that surroundsthe clew 20. As a result, the clew 20 will have a certain inert mass,too, which makes it possible to move said clew 20 through the shed 3 bymeans of a medium under pressure.

The weft yarn 11 formed into a clew 20 unwinds from the foil casing 24at the location indicated at 24 a during its movement through the shed3. At the end of the shed 3, the clew 20 has fully unwound into anelongated weft yarn 11, and the foil encasing is regarded as wastewhich, on account of its low weight, can easily be separated and bedischarged, for example by being exhausted.

Another embodiment of the weft yarn 11 formed into a clew 20 as shown inFIG. 3 a, which has its own consistent shape, uses ice, in particulardry ice, as the binding or bonding agent. Said embodiment may berealised, for example, by moisturising the clew 20 with water andsubsequently freezing it. The ice particles will fragmentize at thelocation where the left yarn 11 is pulled off a clew 20 during themovement through the shed.

It is also possible to compress the clew 20, using carbon dioxide snow(dry ice), while it is being formed, so that a consistent shape can beobtained in this manner as well. In this case, too, the carbon dioxideice will fragmentize upon insertion of the clew 20 into the shed 3. Saidcarbon dioxide ice will subsequently evaporate in the shed 3.

Yet another embodiment is shown in FIG. 3 d, in which the weft yarn 11is wound on a carrier 25 in one or more windings 20 a-20 f, thus forminga clew 20. This carrier, too, has a low inert mass and can be moved or“shot” through the shed 3 by suitable insertion means. The left yarn 11will unwind from the carrier 25 during its movement through the shed 3.In this case, too, the carrier 25 can be intercepted at the end of theshed 3 and be reused.

In all the above embodiments the clew 20 is given a certain consistencyof its own by the addition of means having a low inert mass. Saidconsistency makes it easier to handle the clew, for example position itin the insertion means. In addition it enables the insertion or“shooting” of the clew into the shed at great velocity by the insertionmeans, using a medium under pressure.

It is also possible, however, to wind the weft yarn 11 into a clew 20 ina specific manner without making use of external, foreign auxiliarymeans (a bonding agent, an encasing or a carrier), which clew likewisehas a consistent shape as a result of the winding method that is beingused. This embodiment is shown in FIG. 3E. This embodiment, too, can beinserted into the shed at great velocity by the insertion means, using amedium under pressure.

FIG. 4 shows an embodiment of the insertion means for use with a weavingdevice according to the invention. The insertion means, indicated at 9in FIG. 1, comprise an elongated cube 30 having an open end 30 a, whichis directed towards the shed 3. The other end 30 b is provided with anopening that can be connected or coupled to means for supplying mediumunder pressure.

Present inside the elongated tube 30, which in fact functions as alaunching tube, is a weft yarn 11 formed into a clew 20 in accordancewith any one of the embodiments as shown in FIGS. 2A-2D. The yarnsection 21 projecting from the clew 20 is fixed by the launching tube 30at the location indicated at 30 c. The clew 20 is launched into the shed3 from the tube as a result of the pressure buildup generated by feedinga certain amount of medium under pressure P to the space 31 between thetube 30 and the clew 20 via the opening 30 b. By fixing the yarn section21 in the launching tube 30 at the location indicated at 30 c, thelaunched clew 20 unwinds into a full-length, elongated weft yarn 11 inthe shed 3. After having launched a clew 20, the insertion means 9 maybe readied for inserting a next clew 20 into the shed 3.

Said repeated “loading” and “unloading” of the launching tube 30 with anew clew 20, which, after being launched into the shed 3, unwinds intoan elongated left yarn 11 having a length that is substantially equal tothe width L of the shed 3, can be further automated, especially if thevarious clews 20 are interconnected by means of intermediate yarnsections 21.

This embodiment is shown in FIG. 5 a, which shows several clews 201-206,each comprising a packed weft yarn 111-116, which, in unwound form, hasa length equal to or slightly smaller than the width L of the shed 3.See also FIG. 4. Intermediate yarn sections 211-216 are to be fixed bythe insertion means 9, this in order to enable unwinding of the clew201-206 into an elongated left yarn 11 in the shed 3.

In a specific embodiment, the various clews 201-206 are formed of asingle yarn 26.

FIG. 5 b shows yet another a specific embodiment of the insertion means9, which, in addition to the launching tube 30, also comprise a windingelement 35, on which the various weft yarns 111-1110 formed into clews201-2010 are arranged in one or more windings. Rotation of the windingelement 35 causing the windings of the clews 201-2010 to be unwound inthe direction of the opening 30 c of the launching tube 30. The opening30 c can be opened temporarily and be closed again for passing a clew202, with the intermediate yarn section 211-212 being fixed each timethe tube is opened and closed again.

By supplying medium under pressure via the opening 30 b, the clew isshot into the shed 3, causing it to unwind into an elongated weft yarn112.

Although the invention has been explained herein on the basis of apacked clew being inserted into the shed by the insertion means, using amedium under pressure (compressed air or a water jet), this aspect ofthe insertion means must not be construed as being overly limitative.Also other variants of insertion means are possible, as long as saidmeans in part a movement to the packed clew or the carrier by means ofimpulse transmission. Also such variants are considered to fall withinthe scope of the appended claims.

1. A weaving device comprising means for forming a shed consisting ofwarp yarns, with insertion means being disposed on one side or on bothsides of the shed for inserting a weft yarn into the shed, characterizedin that the weft yarn has been formed into a packed clew, which packedclew unwinds into an elongated weft yarn upon insertion into the shed.2. The weaving device according to claim 1, characterized in that theinsertion means fix the packed clew upon insertion into the shed at ayarn section that projects from the clew.
 3. The weaving deviceaccording to claim 2, characterized in that the insertion means comprisea gripping element for fixing the yarn section.
 4. A The weaving deviceaccording to claim 1, characterized in that the packed clew has its ownconsistent shape.
 5. The weaving device according to claim 4,characterized in that the weft yarn of the packed clew is provided witha bonding agent.
 6. The weaving device according to claim 5,characterized in that said bonding agent is a glue.
 7. The weavingdevice according to claim 5, characterized in that said bonding agent isa wax.
 8. The weaving device according to claim 5, characterized in thatthe said bonding agent is ice.
 9. The weaving device according to claim1, characterized in that the packed clew can be moved through the shedby means of a carrier.
 10. The weaving device according to claim 9,characterized in that the packed clew is arranged round the carrier inone or more windings.
 11. The weaving device according to claim 9,characterized in that the carrier envelopes the packed clew at leastpartially.
 12. The weaving device according to claim 11, characterizedin that the carrier is made of a rigid material, for example a plastic.13. The weaving device according to claim 11, characterized in that thecarrier is made of a flexible material, for example a foil.
 14. Theweaving device according to claim 1, characterized in that the insertionmeans comprise an alonagated tube, which tube is directed towards theshed with an open end thereof and which can be connected to means forsupplying the medium under pressure at its other end.
 15. The weavingdevice according to claim 14, characterized in that said medium underpressure is air.
 16. The weaving device according to claim 14,characterized in that the said medium under pressure is water.
 17. Theweaving device according to claim 1, characterized in that the weft yarnhas a certain, limited length, having at least one end projecting fromthe clew.
 18. The weaving device according to claim 1, characterized inthat the insertion means are arranged for inserting several clewed weftyarns interconnected via intermediate yarn sections one after anotherinto the shed.
 19. The weaving device according to claim 18,characterized in that said several clewed weft yarns are formed of oneyarn.
 20. The weaving device according to claim 18, characterized inthat said several clewed weft yarns are present on a winding element inone or more windings.
 21. The weft yarn for use in a weaving devicecomprising means for forming a shed consisting of warp yarns, withinsertion means being disposed on one side or on both sides of the shedfor inserting the weft yarn into the shed, as defined in according toclaim 1.